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- /* Target-dependent code for GNU/Linux i386.
- Copyright (C) 2000-2022 Free Software Foundation, Inc.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #include "defs.h"
- #include "gdbcore.h"
- #include "frame.h"
- #include "value.h"
- #include "regcache.h"
- #include "regset.h"
- #include "inferior.h"
- #include "osabi.h"
- #include "reggroups.h"
- #include "dwarf2/frame.h"
- #include "i386-tdep.h"
- #include "i386-linux-tdep.h"
- #include "linux-tdep.h"
- #include "utils.h"
- #include "glibc-tdep.h"
- #include "solib-svr4.h"
- #include "symtab.h"
- #include "arch-utils.h"
- #include "xml-syscall.h"
- #include "infrun.h"
- #include "i387-tdep.h"
- #include "gdbsupport/x86-xstate.h"
- /* The syscall's XML filename for i386. */
- #define XML_SYSCALL_FILENAME_I386 "syscalls/i386-linux.xml"
- #include "record-full.h"
- #include "linux-record.h"
- #include "arch/i386.h"
- #include "target-descriptions.h"
- /* Return non-zero, when the register is in the corresponding register
- group. Put the LINUX_ORIG_EAX register in the system group. */
- static int
- i386_linux_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
- const struct reggroup *group)
- {
- if (regnum == I386_LINUX_ORIG_EAX_REGNUM)
- return (group == system_reggroup
- || group == save_reggroup
- || group == restore_reggroup);
- return i386_register_reggroup_p (gdbarch, regnum, group);
- }
- /* Recognizing signal handler frames. */
- /* GNU/Linux has two flavors of signals. Normal signal handlers, and
- "realtime" (RT) signals. The RT signals can provide additional
- information to the signal handler if the SA_SIGINFO flag is set
- when establishing a signal handler using `sigaction'. It is not
- unlikely that future versions of GNU/Linux will support SA_SIGINFO
- for normal signals too. */
- /* When the i386 Linux kernel calls a signal handler and the
- SA_RESTORER flag isn't set, the return address points to a bit of
- code on the stack. This function returns whether the PC appears to
- be within this bit of code.
- The instruction sequence for normal signals is
- pop %eax
- mov $0x77, %eax
- int $0x80
- or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
- Checking for the code sequence should be somewhat reliable, because
- the effect is to call the system call sigreturn. This is unlikely
- to occur anywhere other than in a signal trampoline.
- It kind of sucks that we have to read memory from the process in
- order to identify a signal trampoline, but there doesn't seem to be
- any other way. Therefore we only do the memory reads if no
- function name could be identified, which should be the case since
- the code is on the stack.
- Detection of signal trampolines for handlers that set the
- SA_RESTORER flag is in general not possible. Unfortunately this is
- what the GNU C Library has been doing for quite some time now.
- However, as of version 2.1.2, the GNU C Library uses signal
- trampolines (named __restore and __restore_rt) that are identical
- to the ones used by the kernel. Therefore, these trampolines are
- supported too. */
- #define LINUX_SIGTRAMP_INSN0 0x58 /* pop %eax */
- #define LINUX_SIGTRAMP_OFFSET0 0
- #define LINUX_SIGTRAMP_INSN1 0xb8 /* mov $NNNN, %eax */
- #define LINUX_SIGTRAMP_OFFSET1 1
- #define LINUX_SIGTRAMP_INSN2 0xcd /* int */
- #define LINUX_SIGTRAMP_OFFSET2 6
- static const gdb_byte linux_sigtramp_code[] =
- {
- LINUX_SIGTRAMP_INSN0, /* pop %eax */
- LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77, %eax */
- LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
- };
- #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
- /* If THIS_FRAME is a sigtramp routine, return the address of the
- start of the routine. Otherwise, return 0. */
- static CORE_ADDR
- i386_linux_sigtramp_start (struct frame_info *this_frame)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- gdb_byte buf[LINUX_SIGTRAMP_LEN];
- /* We only recognize a signal trampoline if PC is at the start of
- one of the three instructions. We optimize for finding the PC at
- the start, as will be the case when the trampoline is not the
- first frame on the stack. We assume that in the case where the
- PC is not at the start of the instruction sequence, there will be
- a few trailing readable bytes on the stack. */
- if (!safe_frame_unwind_memory (this_frame, pc, buf))
- return 0;
- if (buf[0] != LINUX_SIGTRAMP_INSN0)
- {
- int adjust;
- switch (buf[0])
- {
- case LINUX_SIGTRAMP_INSN1:
- adjust = LINUX_SIGTRAMP_OFFSET1;
- break;
- case LINUX_SIGTRAMP_INSN2:
- adjust = LINUX_SIGTRAMP_OFFSET2;
- break;
- default:
- return 0;
- }
- pc -= adjust;
- if (!safe_frame_unwind_memory (this_frame, pc, buf))
- return 0;
- }
- if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
- return 0;
- return pc;
- }
- /* This function does the same for RT signals. Here the instruction
- sequence is
- mov $0xad, %eax
- int $0x80
- or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
- The effect is to call the system call rt_sigreturn. */
- #define LINUX_RT_SIGTRAMP_INSN0 0xb8 /* mov $NNNN, %eax */
- #define LINUX_RT_SIGTRAMP_OFFSET0 0
- #define LINUX_RT_SIGTRAMP_INSN1 0xcd /* int */
- #define LINUX_RT_SIGTRAMP_OFFSET1 5
- static const gdb_byte linux_rt_sigtramp_code[] =
- {
- LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad, %eax */
- LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
- };
- #define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
- /* If THIS_FRAME is an RT sigtramp routine, return the address of the
- start of the routine. Otherwise, return 0. */
- static CORE_ADDR
- i386_linux_rt_sigtramp_start (struct frame_info *this_frame)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- gdb_byte buf[LINUX_RT_SIGTRAMP_LEN];
- /* We only recognize a signal trampoline if PC is at the start of
- one of the two instructions. We optimize for finding the PC at
- the start, as will be the case when the trampoline is not the
- first frame on the stack. We assume that in the case where the
- PC is not at the start of the instruction sequence, there will be
- a few trailing readable bytes on the stack. */
- if (!safe_frame_unwind_memory (this_frame, pc, buf))
- return 0;
- if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
- {
- if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
- return 0;
- pc -= LINUX_RT_SIGTRAMP_OFFSET1;
- if (!safe_frame_unwind_memory (this_frame, pc,
- buf))
- return 0;
- }
- if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
- return 0;
- return pc;
- }
- /* Return whether THIS_FRAME corresponds to a GNU/Linux sigtramp
- routine. */
- static int
- i386_linux_sigtramp_p (struct frame_info *this_frame)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- const char *name;
- find_pc_partial_function (pc, &name, NULL, NULL);
- /* If we have NAME, we can optimize the search. The trampolines are
- named __restore and __restore_rt. However, they aren't dynamically
- exported from the shared C library, so the trampoline may appear to
- be part of the preceding function. This should always be sigaction,
- __sigaction, or __libc_sigaction (all aliases to the same function). */
- if (name == NULL || strstr (name, "sigaction") != NULL)
- return (i386_linux_sigtramp_start (this_frame) != 0
- || i386_linux_rt_sigtramp_start (this_frame) != 0);
- return (strcmp ("__restore", name) == 0
- || strcmp ("__restore_rt", name) == 0);
- }
- /* Return one if the PC of THIS_FRAME is in a signal trampoline which
- may have DWARF-2 CFI. */
- static int
- i386_linux_dwarf_signal_frame_p (struct gdbarch *gdbarch,
- struct frame_info *this_frame)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- const char *name;
- find_pc_partial_function (pc, &name, NULL, NULL);
- /* If a vsyscall DSO is in use, the signal trampolines may have these
- names. */
- if (name && (strcmp (name, "__kernel_sigreturn") == 0
- || strcmp (name, "__kernel_rt_sigreturn") == 0))
- return 1;
- return 0;
- }
- /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
- #define I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 20
- /* Assuming THIS_FRAME is a GNU/Linux sigtramp routine, return the
- address of the associated sigcontext structure. */
- static CORE_ADDR
- i386_linux_sigcontext_addr (struct frame_info *this_frame)
- {
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- CORE_ADDR pc;
- CORE_ADDR sp;
- gdb_byte buf[4];
- get_frame_register (this_frame, I386_ESP_REGNUM, buf);
- sp = extract_unsigned_integer (buf, 4, byte_order);
- pc = i386_linux_sigtramp_start (this_frame);
- if (pc)
- {
- /* The sigcontext structure lives on the stack, right after
- the signum argument. We determine the address of the
- sigcontext structure by looking at the frame's stack
- pointer. Keep in mind that the first instruction of the
- sigtramp code is "pop %eax". If the PC is after this
- instruction, adjust the returned value accordingly. */
- if (pc == get_frame_pc (this_frame))
- return sp + 4;
- return sp;
- }
- pc = i386_linux_rt_sigtramp_start (this_frame);
- if (pc)
- {
- CORE_ADDR ucontext_addr;
- /* The sigcontext structure is part of the user context. A
- pointer to the user context is passed as the third argument
- to the signal handler. */
- read_memory (sp + 8, buf, 4);
- ucontext_addr = extract_unsigned_integer (buf, 4, byte_order);
- return ucontext_addr + I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
- }
- error (_("Couldn't recognize signal trampoline."));
- return 0;
- }
- /* Set the program counter for process PTID to PC. */
- static void
- i386_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
- {
- regcache_cooked_write_unsigned (regcache, I386_EIP_REGNUM, pc);
- /* We must be careful with modifying the program counter. If we
- just interrupted a system call, the kernel might try to restart
- it when we resume the inferior. On restarting the system call,
- the kernel will try backing up the program counter even though it
- no longer points at the system call. This typically results in a
- SIGSEGV or SIGILL. We can prevent this by writing `-1' in the
- "orig_eax" pseudo-register.
- Note that "orig_eax" is saved when setting up a dummy call frame.
- This means that it is properly restored when that frame is
- popped, and that the interrupted system call will be restarted
- when we resume the inferior on return from a function call from
- within GDB. In all other cases the system call will not be
- restarted. */
- regcache_cooked_write_unsigned (regcache, I386_LINUX_ORIG_EAX_REGNUM, -1);
- }
- /* Record all registers but IP register for process-record. */
- static int
- i386_all_but_ip_registers_record (struct regcache *regcache)
- {
- if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_ECX_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_EDX_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_EBX_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_ESP_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_EBP_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_ESI_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_EDI_REGNUM))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_EFLAGS_REGNUM))
- return -1;
- return 0;
- }
- /* i386_canonicalize_syscall maps from the native i386 Linux set
- of syscall ids into a canonical set of syscall ids used by
- process record (a mostly trivial mapping, since the canonical
- set was originally taken from the i386 set). */
- static enum gdb_syscall
- i386_canonicalize_syscall (int syscall)
- {
- enum { i386_syscall_max = 499 };
- if (syscall <= i386_syscall_max)
- return (enum gdb_syscall) syscall;
- else
- return gdb_sys_no_syscall;
- }
- /* Value of the sigcode in case of a boundary fault. */
- #define SIG_CODE_BONDARY_FAULT 3
- /* i386 GNU/Linux implementation of the report_signal_info
- gdbarch hook. Displays information related to MPX bound
- violations. */
- void
- i386_linux_report_signal_info (struct gdbarch *gdbarch, struct ui_out *uiout,
- enum gdb_signal siggnal)
- {
- /* -Wmaybe-uninitialized */
- CORE_ADDR lower_bound = 0, upper_bound = 0, access = 0;
- int is_upper;
- long sig_code = 0;
- if (!i386_mpx_enabled () || siggnal != GDB_SIGNAL_SEGV)
- return;
- try
- {
- /* Sigcode evaluates if the actual segfault is a boundary violation. */
- sig_code = parse_and_eval_long ("$_siginfo.si_code\n");
- lower_bound
- = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._lower");
- upper_bound
- = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._upper");
- access
- = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr");
- }
- catch (const gdb_exception &exception)
- {
- return;
- }
- /* If this is not a boundary violation just return. */
- if (sig_code != SIG_CODE_BONDARY_FAULT)
- return;
- is_upper = (access > upper_bound ? 1 : 0);
- uiout->text ("\n");
- if (is_upper)
- uiout->field_string ("sigcode-meaning", _("Upper bound violation"));
- else
- uiout->field_string ("sigcode-meaning", _("Lower bound violation"));
- uiout->text (_(" while accessing address "));
- uiout->field_core_addr ("bound-access", gdbarch, access);
- uiout->text (_("\nBounds: [lower = "));
- uiout->field_core_addr ("lower-bound", gdbarch, lower_bound);
- uiout->text (_(", upper = "));
- uiout->field_core_addr ("upper-bound", gdbarch, upper_bound);
- uiout->text (_("]"));
- }
- /* Parse the arguments of current system call instruction and record
- the values of the registers and memory that will be changed into
- "record_arch_list". This instruction is "int 0x80" (Linux
- Kernel2.4) or "sysenter" (Linux Kernel 2.6).
- Return -1 if something wrong. */
- static struct linux_record_tdep i386_linux_record_tdep;
- static int
- i386_linux_intx80_sysenter_syscall_record (struct regcache *regcache)
- {
- int ret;
- LONGEST syscall_native;
- enum gdb_syscall syscall_gdb;
- regcache_raw_read_signed (regcache, I386_EAX_REGNUM, &syscall_native);
- syscall_gdb = i386_canonicalize_syscall (syscall_native);
- if (syscall_gdb < 0)
- {
- gdb_printf (gdb_stderr,
- _("Process record and replay target doesn't "
- "support syscall number %s\n"),
- plongest (syscall_native));
- return -1;
- }
- if (syscall_gdb == gdb_sys_sigreturn
- || syscall_gdb == gdb_sys_rt_sigreturn)
- {
- if (i386_all_but_ip_registers_record (regcache))
- return -1;
- return 0;
- }
- ret = record_linux_system_call (syscall_gdb, regcache,
- &i386_linux_record_tdep);
- if (ret)
- return ret;
- /* Record the return value of the system call. */
- if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM))
- return -1;
- return 0;
- }
- #define I386_LINUX_xstate 270
- #define I386_LINUX_frame_size 732
- static int
- i386_linux_record_signal (struct gdbarch *gdbarch,
- struct regcache *regcache,
- enum gdb_signal signal)
- {
- ULONGEST esp;
- if (i386_all_but_ip_registers_record (regcache))
- return -1;
- if (record_full_arch_list_add_reg (regcache, I386_EIP_REGNUM))
- return -1;
- /* Record the change in the stack. */
- regcache_raw_read_unsigned (regcache, I386_ESP_REGNUM, &esp);
- /* This is for xstate.
- sp -= sizeof (struct _fpstate); */
- esp -= I386_LINUX_xstate;
- /* This is for frame_size.
- sp -= sizeof (struct rt_sigframe); */
- esp -= I386_LINUX_frame_size;
- if (record_full_arch_list_add_mem (esp,
- I386_LINUX_xstate + I386_LINUX_frame_size))
- return -1;
- if (record_full_arch_list_add_end ())
- return -1;
- return 0;
- }
- /* Core of the implementation for gdbarch get_syscall_number. Get pending
- syscall number from REGCACHE. If there is no pending syscall -1 will be
- returned. Pending syscall means ptrace has stepped into the syscall but
- another ptrace call will step out. PC is right after the int $0x80
- / syscall / sysenter instruction in both cases, PC does not change during
- the second ptrace step. */
- static LONGEST
- i386_linux_get_syscall_number_from_regcache (struct regcache *regcache)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- /* The content of a register. */
- gdb_byte buf[4];
- /* The result. */
- LONGEST ret;
- /* Getting the system call number from the register.
- When dealing with x86 architecture, this information
- is stored at %eax register. */
- regcache->cooked_read (I386_LINUX_ORIG_EAX_REGNUM, buf);
- ret = extract_signed_integer (buf, byte_order);
- return ret;
- }
- /* Wrapper for i386_linux_get_syscall_number_from_regcache to make it
- compatible with gdbarch get_syscall_number method prototype. */
- static LONGEST
- i386_linux_get_syscall_number (struct gdbarch *gdbarch,
- thread_info *thread)
- {
- struct regcache *regcache = get_thread_regcache (thread);
- return i386_linux_get_syscall_number_from_regcache (regcache);
- }
- /* The register sets used in GNU/Linux ELF core-dumps are identical to
- the register sets in `struct user' that are used for a.out
- core-dumps. These are also used by ptrace(2). The corresponding
- types are `elf_gregset_t' for the general-purpose registers (with
- `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
- for the floating-point registers.
- Those types used to be available under the names `gregset_t' and
- `fpregset_t' too, and GDB used those names in the past. But those
- names are now used for the register sets used in the `mcontext_t'
- type, which have a different size and layout. */
- /* Mapping between the general-purpose registers in `struct user'
- format and GDB's register cache layout. */
- /* From <sys/reg.h>. */
- int i386_linux_gregset_reg_offset[] =
- {
- 6 * 4, /* %eax */
- 1 * 4, /* %ecx */
- 2 * 4, /* %edx */
- 0 * 4, /* %ebx */
- 15 * 4, /* %esp */
- 5 * 4, /* %ebp */
- 3 * 4, /* %esi */
- 4 * 4, /* %edi */
- 12 * 4, /* %eip */
- 14 * 4, /* %eflags */
- 13 * 4, /* %cs */
- 16 * 4, /* %ss */
- 7 * 4, /* %ds */
- 8 * 4, /* %es */
- 9 * 4, /* %fs */
- 10 * 4, /* %gs */
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1,
- -1, -1, -1, -1, -1, -1, -1, -1,
- -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
- -1, -1, /* MPX registers BNDCFGU, BNDSTATUS. */
- -1, -1, -1, -1, -1, -1, -1, -1, /* k0 ... k7 (AVX512) */
- -1, -1, -1, -1, -1, -1, -1, -1, /* zmm0 ... zmm7 (AVX512) */
- -1, /* PKRU register */
- 11 * 4, /* "orig_eax" */
- };
- /* Mapping between the general-purpose registers in `struct
- sigcontext' format and GDB's register cache layout. */
- /* From <asm/sigcontext.h>. */
- static int i386_linux_sc_reg_offset[] =
- {
- 11 * 4, /* %eax */
- 10 * 4, /* %ecx */
- 9 * 4, /* %edx */
- 8 * 4, /* %ebx */
- 7 * 4, /* %esp */
- 6 * 4, /* %ebp */
- 5 * 4, /* %esi */
- 4 * 4, /* %edi */
- 14 * 4, /* %eip */
- 16 * 4, /* %eflags */
- 15 * 4, /* %cs */
- 18 * 4, /* %ss */
- 3 * 4, /* %ds */
- 2 * 4, /* %es */
- 1 * 4, /* %fs */
- 0 * 4 /* %gs */
- };
- /* Get XSAVE extended state xcr0 from core dump. */
- uint64_t
- i386_linux_core_read_xcr0 (bfd *abfd)
- {
- asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate");
- uint64_t xcr0;
- if (xstate)
- {
- size_t size = bfd_section_size (xstate);
- /* Check extended state size. */
- if (size < X86_XSTATE_AVX_SIZE)
- xcr0 = X86_XSTATE_SSE_MASK;
- else
- {
- char contents[8];
- if (! bfd_get_section_contents (abfd, xstate, contents,
- I386_LINUX_XSAVE_XCR0_OFFSET,
- 8))
- {
- warning (_("Couldn't read `xcr0' bytes from "
- "`.reg-xstate' section in core file."));
- return 0;
- }
- xcr0 = bfd_get_64 (abfd, contents);
- }
- }
- else
- xcr0 = 0;
- return xcr0;
- }
- /* See i386-linux-tdep.h. */
- const struct target_desc *
- i386_linux_read_description (uint64_t xcr0)
- {
- if (xcr0 == 0)
- return NULL;
- static struct target_desc *i386_linux_tdescs \
- [2/*X87*/][2/*SSE*/][2/*AVX*/][2/*MPX*/][2/*AVX512*/][2/*PKRU*/] = {};
- struct target_desc **tdesc;
- tdesc = &i386_linux_tdescs[(xcr0 & X86_XSTATE_X87) ? 1 : 0]
- [(xcr0 & X86_XSTATE_SSE) ? 1 : 0]
- [(xcr0 & X86_XSTATE_AVX) ? 1 : 0]
- [(xcr0 & X86_XSTATE_MPX) ? 1 : 0]
- [(xcr0 & X86_XSTATE_AVX512) ? 1 : 0]
- [(xcr0 & X86_XSTATE_PKRU) ? 1 : 0];
- if (*tdesc == NULL)
- *tdesc = i386_create_target_description (xcr0, true, false);
- return *tdesc;
- }
- /* Get Linux/x86 target description from core dump. */
- static const struct target_desc *
- i386_linux_core_read_description (struct gdbarch *gdbarch,
- struct target_ops *target,
- bfd *abfd)
- {
- /* Linux/i386. */
- uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd);
- const struct target_desc *tdesc = i386_linux_read_description (xcr0);
- if (tdesc != NULL)
- return tdesc;
- if (bfd_get_section_by_name (abfd, ".reg-xfp") != NULL)
- return i386_linux_read_description (X86_XSTATE_SSE_MASK);
- else
- return i386_linux_read_description (X86_XSTATE_X87_MASK);
- }
- /* Similar to i386_supply_fpregset, but use XSAVE extended state. */
- static void
- i386_linux_supply_xstateregset (const struct regset *regset,
- struct regcache *regcache, int regnum,
- const void *xstateregs, size_t len)
- {
- i387_supply_xsave (regcache, regnum, xstateregs);
- }
- struct type *
- x86_linux_get_siginfo_type (struct gdbarch *gdbarch)
- {
- return linux_get_siginfo_type_with_fields (gdbarch, LINUX_SIGINFO_FIELD_ADDR_BND);
- }
- /* Similar to i386_collect_fpregset, but use XSAVE extended state. */
- static void
- i386_linux_collect_xstateregset (const struct regset *regset,
- const struct regcache *regcache,
- int regnum, void *xstateregs, size_t len)
- {
- i387_collect_xsave (regcache, regnum, xstateregs, 1);
- }
- /* Register set definitions. */
- static const struct regset i386_linux_xstateregset =
- {
- NULL,
- i386_linux_supply_xstateregset,
- i386_linux_collect_xstateregset
- };
- /* Iterate over core file register note sections. */
- static void
- i386_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
- iterate_over_regset_sections_cb *cb,
- void *cb_data,
- const struct regcache *regcache)
- {
- i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- cb (".reg", 68, 68, &i386_gregset, NULL, cb_data);
- if (tdep->xcr0 & X86_XSTATE_AVX)
- cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0),
- X86_XSTATE_SIZE (tdep->xcr0), &i386_linux_xstateregset,
- "XSAVE extended state", cb_data);
- else if (tdep->xcr0 & X86_XSTATE_SSE)
- cb (".reg-xfp", 512, 512, &i386_fpregset, "extended floating-point",
- cb_data);
- else
- cb (".reg2", 108, 108, &i386_fpregset, NULL, cb_data);
- }
- /* Linux kernel shows PC value after the 'int $0x80' instruction even if
- inferior is still inside the syscall. On next PTRACE_SINGLESTEP it will
- finish the syscall but PC will not change.
-
- Some vDSOs contain 'int $0x80; ret' and during stepping out of the syscall
- i386_displaced_step_fixup would keep PC at the displaced pad location.
- As PC is pointing to the 'ret' instruction before the step
- i386_displaced_step_fixup would expect inferior has just executed that 'ret'
- and PC should not be adjusted. In reality it finished syscall instead and
- PC should get relocated back to its vDSO address. Hide the 'ret'
- instruction by 'nop' so that i386_displaced_step_fixup is not confused.
-
- It is not fully correct as the bytes in struct
- displaced_step_copy_insn_closure will not match the inferior code. But we
- would need some new flag in displaced_step_copy_insn_closure otherwise to
- keep the state that syscall is finishing for the later
- i386_displaced_step_fixup execution as the syscall execution is already no
- longer detectable there. The new flag field would mean i386-linux-tdep.c
- needs to wrap all the displacement methods of i386-tdep.c which does not seem
- worth it. The same effect is achieved by patching that 'nop' instruction
- there instead. */
- static displaced_step_copy_insn_closure_up
- i386_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
- CORE_ADDR from, CORE_ADDR to,
- struct regcache *regs)
- {
- displaced_step_copy_insn_closure_up closure_
- = i386_displaced_step_copy_insn (gdbarch, from, to, regs);
- if (i386_linux_get_syscall_number_from_regcache (regs) != -1)
- {
- /* The closure returned by i386_displaced_step_copy_insn is simply a
- buffer with a copy of the instruction. */
- i386_displaced_step_copy_insn_closure *closure
- = (i386_displaced_step_copy_insn_closure *) closure_.get ();
- /* Fake nop. */
- closure->buf[0] = 0x90;
- }
- return closure_;
- }
- static void
- i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
- {
- i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- const struct target_desc *tdesc = info.target_desc;
- struct tdesc_arch_data *tdesc_data = info.tdesc_data;
- const struct tdesc_feature *feature;
- int valid_p;
- gdb_assert (tdesc_data);
- linux_init_abi (info, gdbarch, 1);
- /* GNU/Linux uses ELF. */
- i386_elf_init_abi (info, gdbarch);
- /* Reserve a number for orig_eax. */
- set_gdbarch_num_regs (gdbarch, I386_LINUX_NUM_REGS);
- if (! tdesc_has_registers (tdesc))
- tdesc = i386_linux_read_description (X86_XSTATE_SSE_MASK);
- tdep->tdesc = tdesc;
- feature = tdesc_find_feature (tdesc, "org.gnu.gdb.i386.linux");
- if (feature == NULL)
- return;
- valid_p = tdesc_numbered_register (feature, tdesc_data,
- I386_LINUX_ORIG_EAX_REGNUM,
- "orig_eax");
- if (!valid_p)
- return;
- /* Add the %orig_eax register used for syscall restarting. */
- set_gdbarch_write_pc (gdbarch, i386_linux_write_pc);
- tdep->register_reggroup_p = i386_linux_register_reggroup_p;
- tdep->gregset_reg_offset = i386_linux_gregset_reg_offset;
- tdep->gregset_num_regs = ARRAY_SIZE (i386_linux_gregset_reg_offset);
- tdep->sizeof_gregset = 17 * 4;
- tdep->jb_pc_offset = 20; /* From <bits/setjmp.h>. */
- tdep->sigtramp_p = i386_linux_sigtramp_p;
- tdep->sigcontext_addr = i386_linux_sigcontext_addr;
- tdep->sc_reg_offset = i386_linux_sc_reg_offset;
- tdep->sc_num_regs = ARRAY_SIZE (i386_linux_sc_reg_offset);
- tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET;
- set_gdbarch_process_record (gdbarch, i386_process_record);
- set_gdbarch_process_record_signal (gdbarch, i386_linux_record_signal);
- /* Initialize the i386_linux_record_tdep. */
- /* These values are the size of the type that will be used in a system
- call. They are obtained from Linux Kernel source. */
- i386_linux_record_tdep.size_pointer
- = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
- i386_linux_record_tdep.size__old_kernel_stat = 32;
- i386_linux_record_tdep.size_tms = 16;
- i386_linux_record_tdep.size_loff_t = 8;
- i386_linux_record_tdep.size_flock = 16;
- i386_linux_record_tdep.size_oldold_utsname = 45;
- i386_linux_record_tdep.size_ustat = 20;
- i386_linux_record_tdep.size_old_sigaction = 16;
- i386_linux_record_tdep.size_old_sigset_t = 4;
- i386_linux_record_tdep.size_rlimit = 8;
- i386_linux_record_tdep.size_rusage = 72;
- i386_linux_record_tdep.size_timeval = 8;
- i386_linux_record_tdep.size_timezone = 8;
- i386_linux_record_tdep.size_old_gid_t = 2;
- i386_linux_record_tdep.size_old_uid_t = 2;
- i386_linux_record_tdep.size_fd_set = 128;
- i386_linux_record_tdep.size_old_dirent = 268;
- i386_linux_record_tdep.size_statfs = 64;
- i386_linux_record_tdep.size_statfs64 = 84;
- i386_linux_record_tdep.size_sockaddr = 16;
- i386_linux_record_tdep.size_int
- = gdbarch_int_bit (gdbarch) / TARGET_CHAR_BIT;
- i386_linux_record_tdep.size_long
- = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
- i386_linux_record_tdep.size_ulong
- = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
- i386_linux_record_tdep.size_msghdr = 28;
- i386_linux_record_tdep.size_itimerval = 16;
- i386_linux_record_tdep.size_stat = 88;
- i386_linux_record_tdep.size_old_utsname = 325;
- i386_linux_record_tdep.size_sysinfo = 64;
- i386_linux_record_tdep.size_msqid_ds = 88;
- i386_linux_record_tdep.size_shmid_ds = 84;
- i386_linux_record_tdep.size_new_utsname = 390;
- i386_linux_record_tdep.size_timex = 128;
- i386_linux_record_tdep.size_mem_dqinfo = 24;
- i386_linux_record_tdep.size_if_dqblk = 68;
- i386_linux_record_tdep.size_fs_quota_stat = 68;
- i386_linux_record_tdep.size_timespec = 8;
- i386_linux_record_tdep.size_pollfd = 8;
- i386_linux_record_tdep.size_NFS_FHSIZE = 32;
- i386_linux_record_tdep.size_knfsd_fh = 132;
- i386_linux_record_tdep.size_TASK_COMM_LEN = 16;
- i386_linux_record_tdep.size_sigaction = 20;
- i386_linux_record_tdep.size_sigset_t = 8;
- i386_linux_record_tdep.size_siginfo_t = 128;
- i386_linux_record_tdep.size_cap_user_data_t = 12;
- i386_linux_record_tdep.size_stack_t = 12;
- i386_linux_record_tdep.size_off_t = i386_linux_record_tdep.size_long;
- i386_linux_record_tdep.size_stat64 = 96;
- i386_linux_record_tdep.size_gid_t = 4;
- i386_linux_record_tdep.size_uid_t = 4;
- i386_linux_record_tdep.size_PAGE_SIZE = 4096;
- i386_linux_record_tdep.size_flock64 = 24;
- i386_linux_record_tdep.size_user_desc = 16;
- i386_linux_record_tdep.size_io_event = 32;
- i386_linux_record_tdep.size_iocb = 64;
- i386_linux_record_tdep.size_epoll_event = 12;
- i386_linux_record_tdep.size_itimerspec
- = i386_linux_record_tdep.size_timespec * 2;
- i386_linux_record_tdep.size_mq_attr = 32;
- i386_linux_record_tdep.size_termios = 36;
- i386_linux_record_tdep.size_termios2 = 44;
- i386_linux_record_tdep.size_pid_t = 4;
- i386_linux_record_tdep.size_winsize = 8;
- i386_linux_record_tdep.size_serial_struct = 60;
- i386_linux_record_tdep.size_serial_icounter_struct = 80;
- i386_linux_record_tdep.size_hayes_esp_config = 12;
- i386_linux_record_tdep.size_size_t = 4;
- i386_linux_record_tdep.size_iovec = 8;
- i386_linux_record_tdep.size_time_t = 4;
- /* These values are the second argument of system call "sys_ioctl".
- They are obtained from Linux Kernel source. */
- i386_linux_record_tdep.ioctl_TCGETS = 0x5401;
- i386_linux_record_tdep.ioctl_TCSETS = 0x5402;
- i386_linux_record_tdep.ioctl_TCSETSW = 0x5403;
- i386_linux_record_tdep.ioctl_TCSETSF = 0x5404;
- i386_linux_record_tdep.ioctl_TCGETA = 0x5405;
- i386_linux_record_tdep.ioctl_TCSETA = 0x5406;
- i386_linux_record_tdep.ioctl_TCSETAW = 0x5407;
- i386_linux_record_tdep.ioctl_TCSETAF = 0x5408;
- i386_linux_record_tdep.ioctl_TCSBRK = 0x5409;
- i386_linux_record_tdep.ioctl_TCXONC = 0x540A;
- i386_linux_record_tdep.ioctl_TCFLSH = 0x540B;
- i386_linux_record_tdep.ioctl_TIOCEXCL = 0x540C;
- i386_linux_record_tdep.ioctl_TIOCNXCL = 0x540D;
- i386_linux_record_tdep.ioctl_TIOCSCTTY = 0x540E;
- i386_linux_record_tdep.ioctl_TIOCGPGRP = 0x540F;
- i386_linux_record_tdep.ioctl_TIOCSPGRP = 0x5410;
- i386_linux_record_tdep.ioctl_TIOCOUTQ = 0x5411;
- i386_linux_record_tdep.ioctl_TIOCSTI = 0x5412;
- i386_linux_record_tdep.ioctl_TIOCGWINSZ = 0x5413;
- i386_linux_record_tdep.ioctl_TIOCSWINSZ = 0x5414;
- i386_linux_record_tdep.ioctl_TIOCMGET = 0x5415;
- i386_linux_record_tdep.ioctl_TIOCMBIS = 0x5416;
- i386_linux_record_tdep.ioctl_TIOCMBIC = 0x5417;
- i386_linux_record_tdep.ioctl_TIOCMSET = 0x5418;
- i386_linux_record_tdep.ioctl_TIOCGSOFTCAR = 0x5419;
- i386_linux_record_tdep.ioctl_TIOCSSOFTCAR = 0x541A;
- i386_linux_record_tdep.ioctl_FIONREAD = 0x541B;
- i386_linux_record_tdep.ioctl_TIOCINQ = i386_linux_record_tdep.ioctl_FIONREAD;
- i386_linux_record_tdep.ioctl_TIOCLINUX = 0x541C;
- i386_linux_record_tdep.ioctl_TIOCCONS = 0x541D;
- i386_linux_record_tdep.ioctl_TIOCGSERIAL = 0x541E;
- i386_linux_record_tdep.ioctl_TIOCSSERIAL = 0x541F;
- i386_linux_record_tdep.ioctl_TIOCPKT = 0x5420;
- i386_linux_record_tdep.ioctl_FIONBIO = 0x5421;
- i386_linux_record_tdep.ioctl_TIOCNOTTY = 0x5422;
- i386_linux_record_tdep.ioctl_TIOCSETD = 0x5423;
- i386_linux_record_tdep.ioctl_TIOCGETD = 0x5424;
- i386_linux_record_tdep.ioctl_TCSBRKP = 0x5425;
- i386_linux_record_tdep.ioctl_TIOCTTYGSTRUCT = 0x5426;
- i386_linux_record_tdep.ioctl_TIOCSBRK = 0x5427;
- i386_linux_record_tdep.ioctl_TIOCCBRK = 0x5428;
- i386_linux_record_tdep.ioctl_TIOCGSID = 0x5429;
- i386_linux_record_tdep.ioctl_TCGETS2 = 0x802c542a;
- i386_linux_record_tdep.ioctl_TCSETS2 = 0x402c542b;
- i386_linux_record_tdep.ioctl_TCSETSW2 = 0x402c542c;
- i386_linux_record_tdep.ioctl_TCSETSF2 = 0x402c542d;
- i386_linux_record_tdep.ioctl_TIOCGPTN = 0x80045430;
- i386_linux_record_tdep.ioctl_TIOCSPTLCK = 0x40045431;
- i386_linux_record_tdep.ioctl_FIONCLEX = 0x5450;
- i386_linux_record_tdep.ioctl_FIOCLEX = 0x5451;
- i386_linux_record_tdep.ioctl_FIOASYNC = 0x5452;
- i386_linux_record_tdep.ioctl_TIOCSERCONFIG = 0x5453;
- i386_linux_record_tdep.ioctl_TIOCSERGWILD = 0x5454;
- i386_linux_record_tdep.ioctl_TIOCSERSWILD = 0x5455;
- i386_linux_record_tdep.ioctl_TIOCGLCKTRMIOS = 0x5456;
- i386_linux_record_tdep.ioctl_TIOCSLCKTRMIOS = 0x5457;
- i386_linux_record_tdep.ioctl_TIOCSERGSTRUCT = 0x5458;
- i386_linux_record_tdep.ioctl_TIOCSERGETLSR = 0x5459;
- i386_linux_record_tdep.ioctl_TIOCSERGETMULTI = 0x545A;
- i386_linux_record_tdep.ioctl_TIOCSERSETMULTI = 0x545B;
- i386_linux_record_tdep.ioctl_TIOCMIWAIT = 0x545C;
- i386_linux_record_tdep.ioctl_TIOCGICOUNT = 0x545D;
- i386_linux_record_tdep.ioctl_TIOCGHAYESESP = 0x545E;
- i386_linux_record_tdep.ioctl_TIOCSHAYESESP = 0x545F;
- i386_linux_record_tdep.ioctl_FIOQSIZE = 0x5460;
- /* These values are the second argument of system call "sys_fcntl"
- and "sys_fcntl64". They are obtained from Linux Kernel source. */
- i386_linux_record_tdep.fcntl_F_GETLK = 5;
- i386_linux_record_tdep.fcntl_F_GETLK64 = 12;
- i386_linux_record_tdep.fcntl_F_SETLK64 = 13;
- i386_linux_record_tdep.fcntl_F_SETLKW64 = 14;
- i386_linux_record_tdep.arg1 = I386_EBX_REGNUM;
- i386_linux_record_tdep.arg2 = I386_ECX_REGNUM;
- i386_linux_record_tdep.arg3 = I386_EDX_REGNUM;
- i386_linux_record_tdep.arg4 = I386_ESI_REGNUM;
- i386_linux_record_tdep.arg5 = I386_EDI_REGNUM;
- i386_linux_record_tdep.arg6 = I386_EBP_REGNUM;
- tdep->i386_intx80_record = i386_linux_intx80_sysenter_syscall_record;
- tdep->i386_sysenter_record = i386_linux_intx80_sysenter_syscall_record;
- tdep->i386_syscall_record = i386_linux_intx80_sysenter_syscall_record;
- /* N_FUN symbols in shared libraries have 0 for their values and need
- to be relocated. */
- set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
- /* GNU/Linux uses SVR4-style shared libraries. */
- set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
- set_solib_svr4_fetch_link_map_offsets
- (gdbarch, linux_ilp32_fetch_link_map_offsets);
- /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
- set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
- dwarf2_frame_set_signal_frame_p (gdbarch, i386_linux_dwarf_signal_frame_p);
- /* Enable TLS support. */
- set_gdbarch_fetch_tls_load_module_address (gdbarch,
- svr4_fetch_objfile_link_map);
- /* Core file support. */
- set_gdbarch_iterate_over_regset_sections
- (gdbarch, i386_linux_iterate_over_regset_sections);
- set_gdbarch_core_read_description (gdbarch,
- i386_linux_core_read_description);
- /* Displaced stepping. */
- set_gdbarch_displaced_step_copy_insn (gdbarch,
- i386_linux_displaced_step_copy_insn);
- set_gdbarch_displaced_step_fixup (gdbarch, i386_displaced_step_fixup);
- /* Functions for 'catch syscall'. */
- set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_I386);
- set_gdbarch_get_syscall_number (gdbarch,
- i386_linux_get_syscall_number);
- set_gdbarch_get_siginfo_type (gdbarch, x86_linux_get_siginfo_type);
- set_gdbarch_report_signal_info (gdbarch, i386_linux_report_signal_info);
- }
- void _initialize_i386_linux_tdep ();
- void
- _initialize_i386_linux_tdep ()
- {
- gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_LINUX,
- i386_linux_init_abi);
- }
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